1. Field of the Invention
The present invention relates to liquid separators useful for separating a feed mixture of at least two liquids having different densities, and, more particularly, to such a liquid separator which includes a tangential introduction of a drive fluid.
2. Setting of the Invention
The problem of efficiently separating mixtures of liquids having different densities is well known in many industrial arenas, such as in the recovery of oil. The problem of separating recovered oil from water has spawned the development of numerous types of liquid separation devices, with the most common being hydrocyclones.
A problem encountered in separating oil and water with a hydrocyclone is that the oil and water mixture is introduced at pressures of 100 to 150 psi tangentially into the hydrocyclone. The pumping of this fluid to pressure often results in the oil droplet size becoming finer and harder to remove. Furthermore, under certain temperature and liquid density circumstances, the oil and water does not effectively separate as well as desired because the oil is sheared with the water during the turbulent tangential introduction. Furthermore, introducing the oil/water slurry on the outer diameter tangential entry means that some of the oil droplets must travel all of the way from the outside of the cone to the center. By introducing the liquid mixture centrally into the hydrocyclone, the oil remains in the center as the mixture begins to spin, resulting in a shorter travel distance to effect separation.
If a central introduction of the liquid mixture is used then the separated liquids would be removed from a lower portion of the hydrocyclone. U.S. Pat. No. 4,414,112 discloses a liquid separator wherein the two separated liquids are removed through central lower openings; however, there is no disclosure or suggestion within this patent of introducing the oil and water mixture centrally within the hydrocyclone.